PB2610: EPIDEMIOLOGY AND TREATMENT OF ITP: A SINGLE CENTRE, REAL-WORLD EXPERIENCE
Authors: Priya Patel, Poornima Kumar, Sriram Ravichandran
Journal: HemaSphere (2023)

Topic: 32. Platelet disorders Background: ITP affects around 6.1 per 100,000 adults in the UK. There is a lack of evidence to support strong recommendations for various managements. Short-term steroids and IVIg are the common 1st line treatments in the UK. TPO agonists are available in chronic ITP. Aims: This audit describes the experience of ITP patients from a single centre. Methods: We present the findings of a comprehensive chart review of patients followed in an ITP clinic from 01/10/2010 until 31/09/2022. We define initial response (IR) as platelets >30 x 10 9/L and sustained response (SR) as >100 9/L. During COVID-19, contrary to NICE guidelines, an interim commissioning policy recommended the early use of TPO agonists in acute ITP patients. This has since been withdrawn. Results: 108 patients were analysed. 59% were male. The median age was 56 years (42-73). 68% were White Caucasian. 56.2% presented with mucocutaneous bleeding and the remaining presented with incidental thrombocytopenia. 9 (8.3%) were diagnosed before 2010, 22 (20.4%) were diagnosed in 2010-2015, 52 (48.1%) were diagnosed in 2016-2020, and 25 (23.1%) were diagnosed after 2020. Table 1 shows treatments received by the patients. All 108 patients received 1st line treatment. 80 received 2 lines, 50 received 3 lines and 24 received 4 lines. The average dose of IVIg was 73 grams/dose. The median dose of Eltrombopag was 50 mg/day. The median dose of Romiplostim was 271 mcg/week. The median time to IR after 1st, 2nd, 3rd, and 4th line was 3 days (1-46), 6 days (1-106), 13 days (1-143), and 15 days (1-106), respectively. The median time to SR after 1st, 2nd, 3rd, and 4th lines of treatment was 7 (1-77 days), 9 days (1-99), 13 days (2-407) and 14 days (7-143), respectively. The median time to IR with IVIg in 1st and 2nd line was 3 days (1-19) and 2 days (1-23). The median time to SR with IVIg in 1st and 2nd line was 7.5 days (1-48) and 5 days (4-17). The median time to IR with steroids in 1st and 2nd line was 4 days (1-35) and 3 days (1-72). The median time to SR with steroids in 1st and 2nd line was 6 days (3-25) and 9.5 days (4-31). The median time to SR with Romiplostim and Eltrombopag was 8 days (1-143) and 17 days (2-158). The median duration of remission after 1st, 2nd, and 3rd lines was 5.5 months (0-148 months), 14 months (0-231 months), and 13 months (0-76 months), respectively. Table 1 - Agent 1 st line (n=108) 2 nd line (n=80) 3 rd line (n=50) 4 th line (n=24) IVIg 44 (40%) 17 (21.3%) 4 (8%) 2 (8.3%) Steroids 40 (37%) 18 (22.5%) 4 (8%) 1 (4.2%) IVIg + steroids 16 (14%) 6 (7.5%) 3 (6%) 0 Romiplostim 4 (4%) 11 (13.8%) 12 (24%) 6 (25%) Eltrombopag 3 (3%) 13 (16.3%) 16 (32%) 8 (33.3%) Rituximab 0 13 (16.3%) 9 (18%) 5 (20.8%) Others 2 (2%) 2 (2.5%) 2 (4%) 2 (8.3%) Conclusion: ITP is a chronic disorder; most patients have at least 1 relapse following frontline treatment. Our management of ITP is concordant with current guidelines (2019 Updated International Consensus Report guidelines). IVIg and steroids are the most common 1st line agents, TPO agonists are more commonly used as 2nd line and beyond as these agents are currently not funded for 1st line treatment in the UK. The median duration of remission following 1st line was only 5.5 months. This could be due to the high proportion of patients treated with IVIg at 1st line (IVIg has a short duration of action). ITP carries a significant financial cost: we estimate the cost of IVIg, Romiplostim and Eltrombopag for this cohort at £335800, £15444/week and £16600/week. Given the scarcity, cost, and short duration of response following IVIg, there is a cogent argument to support the early use of TPO agonists. Keywords: ITP, TPO, Chronic ITP, Immune thrombocytopenia (ITP)